The CS-99a has cloth surrounds, so no worry about deteriorating foam there.
I had a pair and sold them. For a 15" driver, their bass is surprisingly weak, most likely due to the too-small box they are in. I did like the craftsmanship very much, however. The drivers are very well-made, and the boxes are heavy and have a very nice veneer. The grills are diffraction nightmares, and should be removed for serious listening.